A lens which is mounted on a monitoring camera, an on-vehicle camera and a camera for a portable apparatus is required to have a viewing angle of 90° or more and to reduce aberration so as to attain sufficient resolution. Further, in a lens constitution of four groups having five lenses, a structure has been proposed that a diaphragm is disposed between the third group and the fourth group and a cemented lens obtained by cementing plastic lenses together is disposed as the fourth group to a rear side (image side) of the diaphragm at a position adjacent to the diaphragm and thereby reduction of cost and improvement of chromatic aberration are attempted (see Japanese Patent No. 5,064,154).
However, even when a cemented lens is disposed to a rear side (image side) of a diaphragm at a position adjacent to the diaphragm like the wide angle lens described in the above-mentioned Patent Literature, other aberration remains and resolution is deteriorated. Further, when a cemented lens is disposed to a rear side of a diaphragm, the absolute value of a radius of curvature of the cemented faces becomes extremely small and thus manufacturing of lenses used for the cemented lens and cementing of the lenses are not performed stably.